1. Field of the Invention
This invention pertains to systems and methods for interconnecting computer peripherals and computing devices. More specifically, the present invention provides a system and method for adapting one or more computer peripherals to a single computer interface slot and for providing an operative connection between the peripheral and the computing device.
2. State of the Art
The present invention generally encompasses interfacing computer peripherals with computers. To understand the benefits derived from the embodiments of the invention to be described herein, it is helpful to understand the existing state of the art and to see why it fails to provide the advantages and benefits of the preferred and alternative embodiments of the present invention. It is also beneficial to a reader to consider the following materials, which are herein incorporated by reference: U.S. patent application Ser. No. 08/399,728 filed on Mar. 7, 1995 and PCT patent application serial no. PCT/US96/03248 filed on Mar. 7, 1996.
The first improvement of the present invention to be described generally pertains to portable computers, but has application with many other types of digital electronic devices. Portable computers are generally understood to include the family of computers known as laptops, notebooks and portables. They are known as portables because they are generally smaller units compared to desktop computers which can more easily be carried from place to place and used at remote locations, often away from plug-in power sources such as AC power outlets. The benefits of mobile computing can be substantial. However, it is often the case that the versatility of these portables is sacrificed for the sake of small size, lower power requirements, and generally any other considerations that make the computer portable. Therefore, peripheral components which are often a part of less easily portable desktop computer systems are not as easily integrated within a portable computer system. These same considerations also apply in the case of many other digital electronic devices.
Because space is limited within a chassis of a portable computer, and power constraints dictate that power drain must be kept to a minimum, most portable computing devices have only one bay which can be used to house only one of various peripheral devices at any given time. This bay is often referred to as a multi-function bay (also referred to herein as a peripheral bay or peripheral slot) when more than one type of peripheral can be inserted therein to communicate with the host portable computer. A floppy drive is often the default peripheral of choice to be placed in the bay because it is used nearly universally for data transfer. However, a CD-ROM drive has also become an almost indispensable peripheral for computers today. Therefore, when a CD-ROM drive is needed, the floppy drive is removed and the CD-ROM drive is inserted in its place, or swapped.
A significant drawback of the single multi-function bay portable computer described above is that only one peripheral device can be used at a time. Furthermore, it was also not mentioned that xe2x80x9chot-swappingxe2x80x9d, or the replacement of one peripheral device with another when the computer is operational, is typically not possible for floppy drives, CD-ROM drives and similar peripherals. Therefore, the portable computer has to be completely powered down before the swap can be made. When more than one peripheral component is needed or when the swapping of two peripherals must be executed more than once, the cycle of powering down, swapping, and then powering up again can become tedious and wasteful of time.
Therefore, it would be an advantage over the prior art to provide a portable computer which can be simultaneously coupled to more than one computer peripheral which can be swapped in and out, and thus take advantage of the ability to have more than one of the computer peripherals electrically coupled to the portable computer, but without having to swap them. These advantages include the ability to have computer peripherals operatively connected directly with a computing device.
The next improvement of the present invention to be described pertains less specifically to the portable computer, and more to the portable computer peripherals which are swapped in and out of the single multi-function bay. Specifically, consider the situation where a portable computer is purchased with some portable computer peripherals. Typically, these portable computer peripherals are the only peripherals which will operatively connect with the portable computer. Notwithstanding the various reasons for this occurrence such as proprietary connectors, pinouts or timing schemes, the result is that portable computer peripherals will often only operatively connect with the portable computers for which they were specifically designed. Now consider that the same user also has a desktop computer. It is often the case that the same peripherals needed for the portable computer are also needed for the desktop computer. Consequently, the user is forced to buy the same peripherals for the desktop computer that were already purchased for the portable computer. The result is needless expense to the user because of redundancy in functionality of peripherals.
It would be an advantage over the prior art to be able to use the portable computer peripherals with the desktop computer despite the proprietary nature common to the computer peripherals.
Accordingly, it is beneficial to a reader to consider the following prior art. A self-adapting interface assembly linking remote peripheral modules to a host computer I/O port via a serial communication cable has been disclosed by Wells, et al, U.S. Pat. No. 5,457,784, wherein circuitry senses the electrical signals present on the cable and automatically configures the hardware and software to reflect the appropriate serial communication interface specification.
The primary disadvantage of such an approach is that the interfaces are limited to simple serial I/O communication links and is not extendable to the more complex computer parallel bus protocols and their associated xe2x80x9cbridgingxe2x80x9d requirements.
Thus, a significant improvement of the present invention features a predetermined and fixed high speed interface adaptation between two of the group that includes both the high speed serial such as USB and Firewire (IEEE1394) and the massively parallel bus protocols such as those conforming to the interface specifications PCMCIA, SCSI, IDE, FDD, and ATAPI, as examples. Further, since the interface protocol and hardware is always fixed and unique to the specific application, the cost and space for the reprogrammable drivers and receivers and the multiple voltage levels of Wells are avoided.
In accordance with yet another improvement of the present invention, provision is made to provide additional current supplying capacity to a computer peripheral, such as a ZIP(trademark) drive, at times when the current supplied by the portable or desktop computer interface is temporarily not sufficient. For example, the current available under some interface standards may be less than that temporarily required by a computer peripheral, such as during load current changes associated with a starting a disk drive motor and moving of the magnetic heads. The present invention provides this supplementary current to maintain the satisfactory operation of the peripheral.
Further, although the above interface standards were designed to operatively connect and provide power for a plurality of peripheral devices, including CD-ROM, fixed disk drives, and removable disk drives, applications using these interfaces were necessarily restricted to short cable lengths due to the voltage drops associated with the cable impedance under transient high current loading conditions. Thus, at the remote end of longer cables, voltages would drop below the minimum input specification requirements of a peripheral device. While it is well known by one skilled in the art that a low cable voltage can be boosted via a converter assembly, also known as a boost voltage regulator in that it provides both the voltage regulation and the DC voltage level shifting functions, this converter assembly is not typically a part of the input circuitry for peripheral devices.
Accordingly, in the present invention, such voltage boosting and regulation means are provided within the bay along with local charge storage devices to provide the supplemental energy needed to support the transient load change, comprising a first capacitor with battery backup located at the input of the voltage regulation means and a second capacitor at the output of the voltage regulation means.
In a related patent, U.S. Pat. No. 5,572,108, Windes discloses a rechargeable battery pack connected through a current limiting circuit, which uses switchable low and high impedances to protect the power source from excessive loading, to a voltage multiplier, and then to a super capacitor bank for AC or DC high voltage, high power commercial applications that are supplied from an intermittent power source. However, this disclosure does not address the steady low power availability associated with the lower power interface connectors of a portable computer, nor the high instantaneous, but low average power associated with a disk drive mechanism. Further, the recharging circuitry for the rechargeable battery introduces added cost that is avoided with a non-rechargeable and higher energy capacity alkaline battery, as in the present invention.
Michelet, et al, in U.S. Pat. No. 3,935,527, discloses a DC voltage source driving a current limiter followed by a DC voltage converter, but has no provisions for battery buffering as in the present invention.
Finally, Crohas, in U.S. Patent Application No. 60/031,510, discloses an assembly using PCMCIA as a voltage source, traditional current limiting circuit, and a load comprising a reader unit, wherein an input buffering means is a capacitor followed by a voltage converter which boosts the voltage applied to a rechargeable battery which is located on the output terminals of the assembly.
This assembly also provides a shutdown mechanism that is activated upon the output voltage of the battery dropping below a threshold value thus protecting the peripheral device from low voltages. Activation of this shutdown threshold, usually about 5% below a nominal output voltage level, will then disconnect the converter output voltage from the output terminals, thus shutting down the peripheral device, which, in turn, usually causes the computer system to shut down.
However, the placement of a rechargeable battery at the output terminals of the assembly represents a significant disadvantage in that under a heavy transient loading which activates the current limiter circuit, a significant portion of the reserve battery charge is blocked by the activation of the shutdown circuitry, as governed by the equation
Q=Cxc3x97Vxe2x80x83xe2x80x83(1)
where Q is the charge, C is the capacitance, and V is the impressed voltage.
Thus, after only a corresponding 5% of the available battery charge being provided to the load, the peripheral device is prematurely shutdown.
In the present invention, however, energy usage is significantly improved with the placement of an alkaline battery at the input of the voltage converter/regulator.
The principal advantage of this configuration over Crohas is that a pulse-width modulated (PWM) converter/regulator is usually operated over a 10-90% duty cycle range to maintain a regulated output voltage, and will thus operate over a significantly wider input voltage range, typically on the order of 25-100% of maximum. Therefore, under the same heavy loading which activates the current limiting circuitry, the same shutdown threshold will still activate at a 5% below nominal output voltage, but that output voltage level will not be reached until the backup battery has discharged approximately 33%, with an attendant 33% drop in battery voltage, and, thus, provided 33% longer operation of the peripheral device compared with the embodiment of Crohas, as governed by the equation
Q=Ixc3x97txe2x80x83xe2x80x83(2)
where t is time.
In view of the above described state of the art, the present invention seeks to realize the following objects and advantages.
It is an object of the present invention to provide a system and method for adapting and interconnecting computer peripherals and computer systems.
It is another object to provide a system and method for simultaneously connecting multiple computer peripherals to a single computer interface slot so that peripheral swapping is unnecessary.
It is still another object to provide a system and method for connecting any of a number of proprietary computer peripherals to a single computer interface slot.
It is yet another object to provide a system and method for connecting portable computer peripherals to a desktop computer so that these peripherals can be shared by both the portable computer and the desktop computer.
It is also an object to provide a system and method for connecting any of a number of proprietary portable computer peripherals to a desktop computer to reduce peripheral redundancy and thereby reduce the cost of peripheral systems to the user.
It is a further object of the present invention to provide a system and method for efficiently powering computer peripherals which temporarily require more power than is supplied by the interface standard used by the computer.
In accordance with these and other objects of the present invention, the advantages of the invention will become more fully apparent from the description and claims which follow, or may be learned by the practice of the invention to be described hereinafter.
The present invention provides a system and method for accomplishing the objective of adapting and interconnecting computer peripherals with portable and desktop computers and other digital computing devices. In a first aspect of the invention, a single interface slot on a computing device is electrically coupled to an interface port of an external docking bay comprised of a plurality of interface slots or ports. Portable peripherals are electrically coupled to the ports of the external docking bay. The computing device is then able to access all of the peripheral devices in the external docking bay which are normally only accessible one at a time when electrically coupled to a port in a multi-function bay made for receiving a single computer peripheral in the portable computer.
In a related aspect of the present invention, the single interface slot to which the external docking bay is electrically coupled is not necessarily the dedicated multi-function port. In other words, a PC card slot (also known as a PCMCIA slot) can also be used to electrically couple the external docking bay to the portable computer, as can the other interfaces previously mentioned.
Another related aspect of the present invention involves overcoming the proprietary characteristic of some interfaces between computer peripherals, particularly portable computer peripherals, and the computer, particularly portable computers and other computing devices. In other words, the present invention can be used where a variety of different proprietary interface standards are encountered.
Another aspect of the present invention is to provide an external docking bay which can be electrically coupled to a hard drive which is incompatible with the IDE interface or some other standard interface which is normally used by the portable computer or other computing device. This enables the external docking bay to act as an interface to the portable computer for devices which could not otherwise be coupled thereto.
Another aspect of the present invention is related to the advantageous capability of electrically coupling portable computer peripherals to a desktop computer or an expansion chassis. An internal docking bay is provided for insertion within a slot or port of the desktop computer. The internal docking bay is thereby electrically coupled to a communications bus within the desktop computer. The internal bay also provides a port which is compatible with an interface port of a portable computer peripheral. The desktop computer is thus able to interface with the portable computer peripherals as if they were inserted into the portable computer. The portable computer peripherals can still be swapped out of the desktop computer and into the portable computer when they are needed there.
A related approach to using the portable peripheral devices with the desktop computer provides for an external docking bay which accepts and electrically connects the portable peripheral device to the docking bay using the interface of the peripheral device, and such docking bay then electrically connecting to a standard interface module located within a cardslot of the desktop computing device using the interface characteristics of the interface module. The interface module is in turn electrically coupled to a communications bus within the desktop computer, thereby establishing the operative link between the peripheral device and the desktop computer.
Another aspect of the present invention is related to electrically coupling a specific desktop peripheral with a portable computer.
Another aspect of the present invention is to provide a tape drive backup unit which is electrically coupled to the portable computer interface port within the multi-function bay.
Yet another aspect of the present invention is to provide a system and method for efficiently powering computer peripherals, such as ZIP(trademark) drives, which intermittently require more power than is supplied an interface standard, such as the PCMCIA interface standard, used by computers.
These and other objects, features, advantages and alternative aspects of the present invention will become apparent to those skilled in the art from a consideration of the following detailed description taken in combination with the accompanying drawings.